In recent years, a touch panel as an input apparatus such as an operation unit for receiving an input operation by an operator has been popularly used for mobile terminals such as mobile phones and gaming machines; information equipments such as calculators and ticket vending machines; home electric appliances such as microwaves, TV sets, lighting equipments; industrial equipment (FA equipment) and the like. Generally, the touch panel is constituted by using a touch sensor disposed on a display unit such as an LCD (Liquid Crystal Display) panel or an EL (Electroluminescence Display) panel.
There are known a variety of types of the touch sensor, such as a resistive film type, a capacitive type, an optical type and the like. However, touch sensors of these types receive a touch input (the input operation) by a touch object such as a finger or a stylus pen and, unlike push-button switches, the touch sensors themselves are not physically displaced when being touched. Since the operator may not obtain feedback to the input when the touch input is received, the operator may not obtain sufficient operability and may feel stressful.
As such, there are suggested a number of techniques to improve the operability by, for example, adding a function to provide feedback to the operator through vibration and the like upon input to the touch sensor and notifying the operator that the input operation is received. For example, there are known techniques that, by changing a pattern of a tactile sensation provided to the operator as feedback based on a position and a pressure on the touch sensor touched, touching duration and the like, increases an information quantity obtained by the operator through tactile sensations in response to an operation and thus further improves the operability (for example, see Patent Documents 1, 2).